Altwied Castle was probably built by Metfried von Wied before 1129 and the first part was completed around 1179. It was enlarged in the 13-14th centuries and the whole village was surrounded by city wall. The castle has newer been conquered, but in the late 17th century it was left uninhabited and later used as a quarry. Today beautiful ruins remain over the Altwied village.
The Royal Palace was built in the first half of the 19th century as the Norwegian residence of King Charles III, who also reigned as king of Sweden and otherwise resided there, and is the official residence of the present Norwegian monarch. The crown prince resides at Skaugum in Asker west of Oslo. The palace has 173 rooms.
Until the completion of the Royal Palace, Norwegian royalty resided in Paleet, the magnificent town house in Christiania that the wealthy merchant Bernt Anker bequeathed to the State in 1805 to be used as a royal residence. During the last years of the union with Denmark it was used by the viceroys of Norway, and in 1814 by the first king of independent Norway, Christian Frederick.